<template>
  <div class="slider" ref="slider">
    <div class="slider-group" ref="sliderGroup">
      <slot>
      </slot>
    </div>
    <div class="dots">
      <span class="dot" :class="{active: currentPageIndex === index }" v-for="(item, index) in dots" :key="index" ref="dot" @touchstart.stop.prevent="selectdot(index)">

      </span>
    </div>
  </div>

</template>
<script type="text/ecmascript-6">
import {addClass} from 'common/js/dom'
import BScroll from 'better-scroll'
import {mapGetters} from 'vuex'
import Scroll from 'base/scroll/scroll'
export default {
  computed:{
    ...mapGetters([
      'ColorActive',
      'variationsList'
    ])
  },
  name: 'slider',
  props: {
    loop: {
      type: Boolean,
      default: true
    },
    autoPlay: {
      type: Boolean,
      default: false
    },
    interval: {
      type: Number,
      default: 4000
    },
    firstLoad: {
      type: Boolean,
      default: true
    }
  },
  data() {
    return {
      dots: [],
      currentPageIndex: 0
    }
  },
  mounted() {
   setTimeout(() => {
      this._setSliderWidth()
      this._initDots()
      this._initSlider()

      if (this.autoPlay) {
        this._play()
      }
    },20)

    window.addEventListener('resize', () => {
      if (!this.slider) {
        return
      }
      this._setSliderWidth(true)
      this.slider.refresh()
    })
  },
  activated() {
    if (this.autoPlay) {
      this._play()
    }
  },
  deactivated() {
    clearTimeout(this.timer)
  },
  beforeDestroy() {
    clearTimeout(this.timer)
  },
  methods: {
    selectdot(index) {
        this.slider.goToPage(index, 0, 400)
    },
    _setSliderWidth(isResize) {

      this.children = this.$refs.sliderGroup.children
      let width = 0
      let sliderWidth = this.$refs.slider.clientWidth
      for (let i = 0; i < this.children.length; i++) {
        let child = this.children[i]
        addClass(child, 'slider-item')

        child.style.width = sliderWidth + 'px'
        width += sliderWidth
      }
      console.log()
      if (this.loop && !isResize && this.children.length > 1) {
        width += 2 * sliderWidth
      }
      this.$refs.sliderGroup.style.width = width + 'px'
    },

    _initSlider() {
      this.slider = new BScroll(this.$refs.slider, {
        scrollX: true,
        scrollY: false,
        momentum: false,
        snap: {
          loop: true,
          threshold: 0.3,
          speed: 400
        },
        click:true
      })

      this.slider.on('scrollEnd', () => {
        let pageIndex = this.slider.getCurrentPage().pageX
        this.currentPageIndex = pageIndex
        this.$emit('getSlideIndex', this.currentPageIndex)

        if (this.autoPlay) {
          this._play()
        }
      })

      this.slider.on('beforeScrollStart', () => {
        if (this.autoPlay) {
          clearTimeout(this.timer)
        }
      })
    },
    _initDots() {
      this.dots = new Array(this.children.length)
    },
    _play() {
      let pageIndex = this.currentPageIndex
      if (this.loop) {
        pageIndex += 1
      }
      this.timer = setTimeout(() => {
        this.slider.goToPage(pageIndex, 0, 400)

      }, this.interval)
    },
    destroyed() {
      clearTimeout(this.timer)
    }
  },
  components: {
    Scroll
  }
}
</script>

<style scoped lang="stylus" rel="stylesheet/stylus">
  @import "~common/stylus/variable"

  .slider
    min-height: 1px
    position: relative
    padding-bottom 30px
    .slider-group
      overflow: hidden
      white-space: nowrap
      .slider-item
        background: #fff
        float: left
        box-sizing: border-box
        overflow: hidden
        text-align: center
        a
          display: block
          width: 100%
          overflow: hidden
          text-decoration: none
    .dots
      position: absolute
      right: 0
      left: 0
      text-align: center
      font-size: 0
      bottom: -1px;
      background-color: #fff;
      padding: 12px 0;
      .dot
        display: inline-block
        margin: 0 4px
        width: 8px
        height: 8px
        border-radius: 50%
        background: #e6e7e8
        &.active
          width: 20px
          border-radius: 5px
          background: #75787b
</style>
